1. Field of the Invention
The present invention relates to an electronic component and a method for manufacturing the same, and specifically relates to an electronic component mounted by soldering and a method for manufacturing the same.
2. Description of the Related Art
As a prior document that discloses a method for forming outer electrodes of an electronic chip component, Japanese Unexamined Patent Application Publication No. 2007-266208 is known. According to the method for forming the outer electrodes of the electronic chip component described in Japanese Unexamined Patent Application Publication No. 2007-266208, chips are bonded to an adhesive sheet, and end surfaces of the chips are immersed into a conductive paste to form a pair of outer electrodes.
In recent years, electronic components such as multilayer ceramic capacitors are required to be large in capacitance and small in size. In order to increase the capacitance of the multilayer ceramic capacitor while reducing its size, it is conceivable to thicken a multilayer body, while thinning outer electrodes, to increase the number of layers of inner electrodes and thereby increasing opposite areas of the inner electrodes.
To thin the outer electrodes, a low-viscosity conductive paste that is easy to separate from the multilayer body may be applied to end surfaces of the multilayer body. However, when the end surfaces of the multilayer body are immersed into the low-viscosity conductive paste, the conductive paste tends to rise on side surfaces of the multilayer body in a short time due to surface tension. Thus, it is difficult to adjust the amount of the conductive paste rising on the end surfaces, causing variations in the shape of the two outer electrodes formed by immersion of both the end surfaces.
The low-viscosity conductive paste rises by different amounts between a middle portion and a ridge portion in each side surface of the multilayer body. To be more specific, the more distant from the ridge portions, the higher the conductive paste rises on the side surface of the multilayer body. Thus, when the outer electrodes are formed by immersing both the end surfaces of the multilayer body into the low-viscosity conductive paste, each outer electrode tends to have a substantially arc shape in a side view in a portion situated on the side surface of the multilayer body at an edge on an opposite side from the end surface of the multilayer body.
In general, the electronic component is mounted on a printed circuit board by soldering, while establishing correspondences between the pair of outer electrodes and a pair of lands provided in the printed circuit board.
In a case where the amount of the rising conductive paste varies and the pair of outer electrodes have asymmetrical shapes, upon soldering the electronic component, a tensile stress applied to the electronic component may lose its balance, owing to thermal shrinkage of a solder fillet. A tombstone phenomenon in which one of the pair of outer electrodes comes off the printed wiring board and the electronic component is erected on the printed circuit board may occur.
Also, in a case where the outer electrodes are each substantially in the arc shape in the side view in the portion situated on the side surface of the multilayer body at the edge on the opposite side from the end surface of the multilayer body, since the tensile stress caused by the distortion of the printed circuit board on which the electronic component is mounted concentrates on the ridge portions, cracks may occur in the multilayer body.